1. Field of the Invention
The present invention relates to a plasma processing method and a plasma processing apparatus capable of being used for manufacturing a color filter or the like.
2. Related Art
As shown in FIG. 6A, a color filter is provided with a glass plate 1 as a base member and a black matrix 2 formed on the glass plate 1. The black matrix 2 includes a number of fine concave portions 3, and coloring inks 4, 5 and 6 for RGB (Red, Green and Blue) are filled into each of the corresponding concave portions 3, whereby the respective pixels for RGB are formed on the glass plate 1.
As a method of manufacturing such color filter, there has been conventionally used a pigment dispersion method or the like in which a photolithography process is repeatedly performed for several times. In recent years, however, an ink-jet apparatus has been used for manufacturing the color filter. The manufacturing method using the ink-jet apparatus comprises the steps of forming the black matrix 2 on the glass plate 1, moving a scanning head of the ink-jet apparatus so as to scan a surface of the glass plate 1, spraying micro droplets of the coloring inks 4, 5 and 6 for RGB colors, and charging (filling) the coloring inks 4, 5 and 6 into the respective concave portions 3 of the black matrix 2 to thereby form the respective pixels for RGB colors on the base material (glass plate) as shown in FIG. 6A.
However, due to differences in properties of the black matrix, the coloring inks 4, 5 and 6 and the glass plate 1, there is caused a case where, for example, the coloring inks 4, 6 do not correctly fill the concave portions 3 of the black matrix 2 as shown in FIG. 6B. If this coloring ink 4 is for R, B colors, portions lacking the R, B colors are revealed as white voids on a display using this color filter. Further, as shown in FIG. 6C, there is caused a case where the coloring inks 4, 5 are mutually mixed to each other at a portion between adjacent concave portions 3, 3 of the black matrix 2. In this case, color dots blur, and the correct colors cannot be displayed.
In order to prevent the above defects such as the white voids, the color mixing and the like, there has been proposed a countermeasure in which the glass plate 1 formed with the black matrix 2 is subjected to a plasma processing as proposed in, for example, Japanese Patent No. 3328297 (Patent Publication 1). In this countermeasure, an organic material is contained in the black matrix 2, and the plasma processing is performed to the glass plate 1 from an upper surface side of the black matrix 2 under a condition that a degree of non-affinity of the coloring inks 4, 5 and 6 with respect to the surface of the black matrix 2 becomes higher than that with respect to the surface of the glass plate 1.
As an apparatus for performing the above plasma processing, it is possible to utilize an apparatus which includes a fixed electrode and a plate-shaped movable electrode moving under the fixed electrode, as disclosed in, for example, Japanese Unexamined Patent Application Publication No. 2002-320845 (JP-A 2002-320845: Patent Publication 2).
In the apparatus mentioned above, when the glass plate is fixed onto the movable electrode, and while the movable electrode is moved under the fixed electrode, voltage is applied to both the electrodes, and a process gas is introduced to a portion between the both electrodes, a plasma generated at a space between the both electrodes can be radiated to the glass plate. Due to this plasma processing, the degree of non-affinity of the black matrix 2 with respect to the coloring inks 4, 5 and 6 is increased. As a result, when the coloring inks 4, 5 and 6 for the respective pixels are sprayed to the glass plate 1 by using an ink-jet printing method at a subsequent manufacturing step, the disadvantages or defects as indicated in FIGS. 6B and 6C can be eliminated to some extent.
However, when the movable electrode is moved, there is a case where an ambient air (outside air) a is introduced from right and left sides with respect to the moving direction of the movable electrode and the ambient air a is involved into a plasma processing space between the movable electrode and the glass plate. When such ambient air a is involved into the plasma processing space, fluorine, for example, contained in the process gas is combined to hydrogen of water vapor contained in the ambient air a, so that bondage (bonding) between the fluorine component and the black matrix is obstructed, and the black matrix becomes liable to peel off from the glass plate as a processing object. Further, the non-affinity of the black matrix with respect to the ink is lowered, or the affinity of the glass plate 1 is retarded, so that the disadvantages or defects indicated in FIGS. 6B and 6C are still caused.
In order to prevent these defects, a conventional plasma processing apparatus is configured as shown in FIG. 7 in which the plasma processing space is formed between the movable electrode 7 and the glass plate 1, and both the end portions of the plasma processing space are blocked by blocking members 14 provided to both the end portions of the movable electrode, the end portions being in relatively parallel with the moving direction of the movable electrode. As a result, the ambient air a is suppressed from invading into the plasma processing space as proposed in the Japanese Unexamined Patent Application Publication No. 2005-19150 (JP-A 2005-19150: Patent Publication 3).
According to the conventional plasma processing method, as shown in FIG. 7, the blocking member 14 is formed so as to project from a side of the movable electrode 7 toward a side of the fixed electrode 8 to thereby form a slight gap at tip end portion of the blocking member 14, and accordingly, the ambient air a enters into the plasma processing space through the gap. This entering ambient air a flows and reaches to a surface of the glass plate 1, which is positioned at level higher than that of the gap. The entering ambient air a becomes a factor to cause the plasma processing defects as mentioned hereinbefore. Therefore, the defects or disadvantages shown in FIGS. 6B and 6C still occur, thus being inconvenient.